Attribute VB_Name = "modGetMACAddress"
Private Const NCBASTAT As Long = &H33
Private Const NCBNAMSZ As Long = 16
Private Const HEAP_ZERO_MEMORY As Long = &H8
Private Const HEAP_GENERATE_EXCEPTIONS As Long = &H4
Private Const NCBRESET As Long = &H32

Private Type NET_CONTROL_BLOCK  'NCB
    ncb_command As Byte
    ncb_retcode As Byte
    ncb_lsn As Byte
    ncb_num As Byte
    ncb_buffer As Long
    ncb_length As Integer
    ncb_callname As String * NCBNAMSZ
    ncb_name As String * NCBNAMSZ
    ncb_rto As Byte
    ncb_sto As Byte
    ncb_post As Long
    ncb_lana_num As Byte
    ncb_cmd_cplt As Byte
    ncb_reserve(9) As Byte ' Reserved, must be 0
    ncb_event As Long
End Type

Private Type ADAPTER_STATUS
    adapter_address(5) As Byte
    rev_major As Byte
    reserved0 As Byte
    adapter_type As Byte
    rev_minor As Byte
    duration As Integer
    frmr_recv As Integer
    frmr_xmit As Integer
    iframe_recv_err As Integer
    xmit_aborts As Integer
    xmit_success As Long
    recv_success As Long
    iframe_xmit_err As Integer
    recv_buff_unavail As Integer
    t1_timeouts As Integer
    ti_timeouts As Integer
    Reserved1 As Long
    free_ncbs As Integer
    max_cfg_ncbs As Integer
    max_ncbs As Integer
    xmit_buf_unavail As Integer
    max_dgram_size As Integer
    pending_sess As Integer
    max_cfg_sess As Integer
    max_sess As Integer
    max_sess_pkt_size As Integer
    name_count As Integer
End Type


Private Type NAME_BUFFER
    name As String * NCBNAMSZ
    name_num As Integer
    name_flags As Integer
End Type

Private Type ASTAT
    adapt As ADAPTER_STATUS
    NameBuff(30) As NAME_BUFFER
End Type

Private Declare Function Netbios Lib "netapi32.dll" _
    (pncb As NET_CONTROL_BLOCK) As Byte

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" _
    (hpvDest As Any, ByVal _
    hpvSource As Long, ByVal _
    cbCopy As Long)

Private Declare Function GetProcessHeap Lib "kernel32" () As Long


Private Declare Function HeapAlloc Lib "kernel32" _
    (ByVal hHeap As Long, ByVal dwFlags As Long, _
    ByVal dwBytes As Long) As Long

Private Declare Function HeapFree Lib "kernel32" _
    (ByVal hHeap As Long, _
    ByVal dwFlags As Long, _
    lpMem As Any) As Long


Public Function GetMACAddress() As String

'retrieve the MAC Address for the network controller
'installed, returning a formatted string

    Dim tmp As String
    Dim pASTAT As Long
    Dim NCB As NET_CONTROL_BLOCK
    Dim AST As ASTAT

'The IBM NetBIOS 3.0 specifications defines four basic
'NetBIOS environments under the NCBRESET command. Win32
'follows the OS/2 Dynamic Link Routine (DLR) environment.
'This means that the first NCB issued by an application
'must be a NCBRESET, with the exception of NCBENUM.
'The Windows NT implementation differs from the IBM
'NetBIOS 3.0 specifications in the NCB_CALLNAME field.
    NCB.ncb_command = NCBRESET
    Call Netbios(NCB)

'To get the Media Access Control (MAC) address for an
'ethernet adapter programmatically, use the Netbios()
'NCBASTAT command and provide a "*" as the name in the
'NCB.ncb_CallName field (in a 16-chr string).
    NCB.ncb_callname = "* "
    NCB.ncb_command = NCBASTAT

'For machines with multiple network adapters you need to
'enumerate the LANA numbers and perform the NCBASTAT
'command on each. Even when you have a single network
'adapter, it is a good idea to enumerate valid LANA numbers
'first and perform the NCBASTAT on one of the valid LANA
'numbers. It is considered bad programming to hardcode the
'LANA number to 0 (see the comments section below).
    NCB.ncb_lana_num = 0
    NCB.ncb_length = Len(AST)

    pASTAT = HeapAlloc(GetProcessHeap(), HEAP_GENERATE_EXCEPTIONS _
    Or HEAP_ZERO_MEMORY, NCB.ncb_length)

    If pASTAT = 0 Then
      Debug.Print "memory allocation failed!"
     Exit Function
    End If

    NCB.ncb_buffer = pASTAT
    Call Netbios(NCB)

    CopyMemory AST, NCB.ncb_buffer, Len(AST)

    tmp = Format$(Hex(AST.adapt.adapter_address(0)), "00") & " " & _
    Format$(Hex(AST.adapt.adapter_address(1)), "00") & " " & _
    Format$(Hex(AST.adapt.adapter_address(2)), "00") & " " & _
    Format$(Hex(AST.adapt.adapter_address(3)), "00") & " " & _
    Format$(Hex(AST.adapt.adapter_address(4)), "00") & " " & _
    Format$(Hex(AST.adapt.adapter_address(5)), "00")


    HeapFree GetProcessHeap(), 0, pASTAT

    GetMACAddress = tmp

End Function
'--end block--'



